


Fluorescent Adolescents

by MiladyMorningstar (PrincessPestilence)



Category: Harry Potter - J. K. Rowling
Genre: Adolescent Sexuality, Birthday Sex, Birthday Smut, Classroom Sex, Cunnilingus, Desk Sex, F/M, Fingerfucking, First Kiss, First Time, Friends With Benefits, Friends to Lovers, Marauders' Era, Pre-Canon, Pre-Series, Vaginal Fingering, Vaginal Sex
Language: English
Status: Completed
Published: 2016-01-30
Updated: 2016-01-30
Packaged: 2018-05-10 20:53:22
Rating: Explicit
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 4,488
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/5600434
Author URL: https://archiveofourown.org/users/PrincessPestilence/pseuds/MiladyMorningstar
Summary: <blockquote class="userstuff">
              <p>Lily knows what she wants for her birthday.<br/>*<br/>"The best you ever had is just a memory"</p>
            </blockquote>





	Fluorescent Adolescents

**Author's Note:**

> There's not enough snily in my life.
> 
> Happy Birthday, Lily!
> 
> (title from [Fluorescent Adolescent](https://www.youtube.com/watch?v=ma9I9VBKPiw) by the Arctic Monkeys.)
> 
> Rest in Peace, Alan Rickman

Lily shrieks as the Gryffindor table suddenly erupts in a flurry of confetti, the multicoloured paper whizzing around the table before migrating back to circle her head, a tinny, disembodied rendition of Happy Birthday permeating the air. The teen blushes bright enough to match her hair and hides her face behind her hands in giddy mortification.

 

“Happy birthday, Lily!” the table screams in unison as the redhead peaks through her fingers.

 

“Stop hiding, Lils,” Mary laughs, pulling the prefect's hands away and replacing them with a card and a large, bright pink package.

 

Lily grins and hugs her friend, opening the card first to be polite before tearing into the hot-pink wrapping paper. The box was large and square, and buried in miles of tissue paper was the new Celestina Warbeck album she'd been gushing about all last term.

 

Lily hugs the record to her chest. “Thank you!” she says, leaning over to accept another hug.

 

Once released, Lily pushes her breakfast plate away and deposites the unreasonably large box on the floor by her bag. Setting the vinyl aside, she began to accept the rest of her gifts. A dozen cards with more or less the same generic well-wishing, and a pre-paid gift certificate to Cordwainer's Quality Footwear from Marlene, which Lily fully intended to use at her next Hogsmeade weekend. Remus handed her a slightly used, thrift store copy of a lurid romance novel, cover featuring a witch in Victorian dress swooning deeply in the arms of a well muscled vampire. The redhead gave a withering glare and the other prefect only laughed, appeasing her by also gifting her a large block of well made German chocolate, coffee flavoured, like she liked. Potter and Black gave her a queerly floral printed stuffed deer (which she admit was actually rather adorable), and a bouquet of wolf-whistling tiger lilies, respectively.

 

Breakfast went on as usual after that, Lily thanking everyone sincerely (with the exception of Sirius Black, whom she sneered at before eyeing the flowers warily. She had no idea how Remus could be friends with that idiot. Potter was just as bad most of the time, but she actually kind of liked his present.) before packing all of the cards and presents into her bag and vanished all the envelopes and wrapping paper, along with Mary's large box.

 

As the clock tolled and the Great Hall began to disperse, Lily stuffed the remainder of her jam-covered muffin in her mouth, hauled her overstuffed bag up over her shoulder (it had a lightening charm on it to prevent what possibly could have been back injuries or maybe a severe case of scoliosis with all the large textbooks crammed inside) and half-jogged across to the opposite entrance, catching up with Severus outside the large, oaken doors.

 

“Mmmph!” Lily intones in muffled greeting, cheeks bulging a bit like a chipmunk as she tried to chew with her mouth closed.

 

Severus smirks down at her in amusement. “Charming,” he drawls. “You've got a bit of jam, just there...” he informs her, pointing toward the corner of his own mouth. Lily wiped the spot away with her thumb as she swallows.

 

“You Gryffindors with your appalling table manners,” the Slytherin mocks imperiously, though his glittering eyes belie his teasing. “When I was your age, I had perfect etiquette; but then, we Slytherins tend to learn these things at a much younger age, you understand.”

 

Lily snorts and rolls her eyes. “You're not even a full month older than me, Sev; what are you even talking about? Don't you talk to me about table manners; I've seen you eat spaghetti,” she reminds him, eyebrow raised in challenge as she brushes the crumbs off her hands.

 

Severus sniffs, raising his nose haughtily and brushing a lock of black hair behind his ear. “Please, I was ten. Nothing that happened before Hogwarts counts.”

 

“Uh-huh, sure,” Lily nods indulgently. Severus looks down at her from the corner of his eye, and his mouth twitches. The Gryffindor grins and nudges him with her shoulder, lacing their arms.

 

“So how does it feel to be sixteen, finally?” the tall boy asks. “Do you feel different?”

 

“Oh yes, terribly,” the redhead agrees facetiously as they make their way down to the dungeons for first period Potions.

 

The two are among the first to file into the classroom. Slughorn hadn't made his appearance yet, and they take their seat in the second row as other students filed in. Lily dug around in her disorganised bag and hauled out the Potions text as well as a lined, muggle spiral notebook and fountain pen before turning in her seat to face her friend.

 

“So,” she prompts. “What did you get me?”

 

Severus ignores her for several seconds, lining his books up pedantically and turning to a blank page in his notebook (Lily's parents had dragged them to buy school supplies with Petunia over the summer), inscribing the date in the top left corner.

 

“I don't know what you mean,” he eventually says, never looking up from his notes.

 

“Sever _uuus_!” Lily whines, leaning over to prop her chin on his bony shoulder. “It's my birthday Sev! You didn't get your _best friend_ something for her birthday?”

 

The Slytherin shrugs, though he's careful not to dislodge her. “ _Some_ of us don't get allowances from their parents, you know. It's a bit difficult to buy something when you haven't got any money.”

 

Lily pulls away, stomach sinking guiltily. “Shit, Sev, I'm sorry. I wasn't thinking, I didn't mean-”

 

Severus sighs loudly and rolled his eyes, finally turning to look at her in fond exasperation. The Slytherin wraps his arm around her shoulders and pulled her back to him. “For God's sake, Lily I was only teasing. Of _course_ I got you a birthday present.”

 

Lily glares and punches him in the shoulder. “You prat! You made me feel bad. I thought I'd offended you or something.”

 

“I'm sorry,” he apologises, pressing a kiss to the top of her head. “Here,” he places a small, rectangular box on top of her notebook. It's unwrapped, the lid bearing an unfamiliar logo, but it looked expensive. Lily's eyes widen, and she looks at Severus curiously, but he only nods toward it, gesturing for her to open it.

 

Lily removes the top lid, and the thin sheet of tissue paper from the top to reveal a gorgeous, multilayered charm bracelet. The redhead gasps, slapping a hand over her mouth.

 

“Oh, Sev, it's beautiful! I love it! How did you afford this?” She carefully held it up to view; a white chain, a gold chain, and a strand of pearls wrapped loosely around one another, decorated with pastel beads, a butterfly charm on one side and a delicate-looking rose on the other. It was simple, and not terribly fancy, but neither was it plain or cheap looking. Lily thought it was perfect.

 

The Slytherin shrugs evasively, a shy smile on his face. “You like it?”

 

Lily nods vehemently. “It's perfect,” she proclaimes. “Put it on me.” She thrusts her arm out and hands Sev the bracelet. He takes it from her gently and fastensit around her wrist, face a solemn mask of concentration as he spins it round to display the charms. His eyes are bright as he pulls his hand away, admiring the jewellery against her pale skin.

 

The Gryffindor grins, holding her arm aloft in front of her, charms tinging as they dangled, clashing lightly into the chains.

 

“Thank you,” she says, leaning over to press her lips against Severus' cheek.

 

The boy blushes, eyes cast down. “Of course,” he mumbles, the words almost swallowed up by Slughorn as he bumbles into the classroom, bidding the students to please take their seats.

 

“And a 'happy birthday' to you, Miss Evans,” the potions master says as he passes their table. “Oh, what a lovely bracelet you've got there, too. It suits you well!” Lily smiled in thanks, but the professor had already passed her on his way to his desk.

 

“If you could all turn in your books to page 412, we can begin. Now, Wednesday, we discussed doxy eggs and their role in stimulant potions, but the _venom_ can actually be used to...”

 

*

 

The fifth year prefects partner up together as they usually did to take prowl the sub-levels of the castle in search for students out of their dorms, Remus and Mavaureen Yaxley, the other fifth year Slytherin, long since used to switching partners during their rounds.

 

As usual, there were a few Hufflepuffs and Slytherins making use of the kitchens after hours, who Lily shooed away after docking house points and one particularly amorous sixth year Slytherin couple who ran away, half-dressed after they were found in the Deathday Party Hall, Severus shouting after them.

 

“Honestly, as if there aren't plenty of places to shag in the dorms,” Sev complains, shaking his head, picking up an unused condom from the floor, still in the wrapper.

 

“Oh are there?” Lily asks curiously, grinning as they continued down the hallway.

 

The Slytherin nods. “We have private guest rooms for rent for that express purpose.”

 

Lily's jaw drops. “Seriously?”

 

Severus smirks at her shocked expression. “Slytherins are very serious about sex. There are workshops on how to be a good lover, on how domination and submission and safe kink. You know the party that goes on every weekend?” Lily nods; Slytherins are famous for their parties, “Well in the hallway outside the second common room, where the rooms for rent are, it actually works as a fully functioning brothel. I actually work the receptionist desk. It's how I afforded your bracelet, to be honest.”

 

“Oh my God.” No _wonder_ the Slytherins parties were so popular, between the liquor and the sex. “Have _you_ ever...?” she ponders curiously, strangely anxious of the answer.

 

To her relief, Severus shakes his head, long hair swaying around his angular face. “No, you have to be sixteen go any further than the front desk. There's a lock tuned to your wand. You can't get passed 'til you're of age, and I only just turned sixteen earlier this month.” He sweeps a hand down the length of his body. “Completely virginal, I'm afraid,” he confesses, a wry, self deprecating smile on his lips.

 

“Oh,” Lily says, blushing, raising her hand to brush her hair behind her ear before realising it was already tied up in a ponytail, her fingers fiddling with the collar of her shirt instead.

 

“D'you want to fix that?”

 

Lily's eyes widen and she feels her face go up in flames, Severus freezing mid-step, head whipping around to stare at her in incredulous shock. Why did she say that? She didn't mean to say that, the words having tumbled out of her mouth of their own accord.

 

“W-what?” Severus stutters, his usual composure gone in the wake of his baffled confusion as he tries to comprehend Lily's offer.

 

“I...” Lily starts, eyes roaming the hallway for an escape or distraction of some kind, or perhaps an explanation over who took control of her wayward mouth. Finding nothing, the Gryffindor swallows and bites her lip. Nervously she ploughs onward, looking everywhere but at her friend, “Only, I am as well, you know. A virgin, that is. I've never... And, I mean, I've never really had a boyfriend, either...” Her heart was racing, stuck in her throat, and she summons all of her courage to look Severus in the face. The Slytherin's face was still uncharacteristically open with shock, face as flushed as her own felt, but he didn't look offended or uncomfortable.

 

Hope sparked in her chest.

 

“And it _is_ my birthday,” she contends, squaring her shoulders as she stares into Sev's wide, dark eyes. “We're of age now, and I want my first time to be someone I trust; someone I care about.” Lily licks her lips and Severus' eyes drop, catching the movement before mimicking the action. She steps closer and grabs his hand, large and warm in her own. “You've been my best friend for seven years, Sev. There isn't anyone else I'd rather have as my first.”

 

The Slytherin still didn't respond, and Lily felt dread curdling in her stomach. Dropping his hand, she back-peddles. “Of course you can say no if you don't want to. It's not a big deal, it won't change anything if you'd rather not, I just thought that, maybe-”

 

“Yes.”

 

Her mouth closes with an audible click. “Really?”

 

Severus nods, clearing his throat. “Yeah. I want to. I mean, if you-” Lily doesn't wait for him to finish, instead taking his hand once more and pulling him into the nearby potions classroom, closing and locking the door behind them. She turns to kiss him, unable to stop herself now that they were actually going to do this, but it seemed Severus was already a step ahead of her.

 

A large hand cups her jaw, tilting her head up as he ducks down and presses his mouth to hers. He's shaking, lips moving minutely against her own and Lily inhales through her nose before relaxing into it, arms coming up to wrap around his shoulders, their lips moving in tandem.

 

Lily takes his top lip between her own sucking lightly before moving her attention to the other, Sev's tongue tracing the seam of her lips, and Lily openes to his perusal, her tongue rubbing sensually against his before drawing back as the Gryffindor pulled away. Severus chases her instinctively before coming to his senses, eyes fluttering open. They stare at each other, panting, sharing breaths as Sev traces the tip of his Roman nose down her freckled cheek.

 

“Desk,” the Slytherin urges resolutely, and Lily nods. Flat surface, perfect. She backs up toward one of the Slytherin work tables, but Severus halts her, shaking his head. “Not _those_ desks,” he corrects, “ _Slughorn's_ desk.” He nodded up the aisle to the ostentatious mahogany monstrosity at the front of the classroom.

 

The birthday girl gapes in surprise. “ _Severus_ ,” she intones severely, mouth twitching into a mischievous smile. “You _rebel_.”

 

Severus grins predatorily. “We're already breaking the rules, we may as well do it in style,” he argues, leading Lily down to the front.

 

The Gryffindor steps out of her loafers and hops up onto the desk. Severus wastes no time stepping up between her knees, claiming her mouth again, confident now, the second time. Lily shivers as his fingers graze the outside of her thighs, teasing the hem of her skirt before passing over it to slide up her shirt instead. She groans into his mouth as he slides his palms up her ribs, cupping her breasts over her bra, newly bought over Christmas break, worn special for the occasion.

 

As Severus licks the roof of her mouth, thumbs brushing over the peaks of her nipples through the lace of her bra, Lily hastily tugs at his tie, pulling it off and dropping it carelessly to the floor as she unbuttons his shirt.

 

Sev shrugs his shirt off his shoulders, and pulls away to remove Lily's own tie, Lily carelessly hauling her shirt up over her head, turning it inside out in her haste before throwing it down, Pulling Severus close to feel his skin against hers. He groans deeply, voice a low, rumbling baritone as she attacks his throat, biting and sucking at the pale skin, feeling his pulse beat a rapid staccato against her tongue. Her hands roam down his chest, fingers dragging through the thin trail of dark hair between his pectorals that lead down into the depths of his trousers. He's lanky and skinny and she can feel the knobs of his spine when she wraps her arms around his back, but he's tall and sturdy against her, the grassy scent of his fougère cologne permeating her senses. His long, deft fingers waste no time unclasping the clips of her bra, tearing the lingerie off and throwing it to the ground.

 

“Hey!” she complains breathlessly. “Careful with that, it's new!”

 

“Sorry,” he pants, trailing kisses across her cheek, tongue flicking against her ear. “It's beautiful.”

 

Lily laughs, the sound breaking off into a gasp as Sev finds a particularly sensitive spot. “You didn't even see it.”

 

He shakes his head, pressing forward so she falls back. “Doesn't matter,” he mumbles, licking one hardened bud into his mouth as she props herself up on her elbows, moaning reedily. “You're always beautiful. I'm sure it was lovely.”

 

Lily blinks, the haze of her lust clearing momentarily even as she arches up into his attentions, mind catching on the unexpectedly earnest honesty of Severus' declaration. She looks down at him, now trailing hot, open mouthed kisses down her soft belly, completely lost in rapture. A soft mewl falls from her lips as he nibbles on the sensitive skin below her navel and she rakes her fingers through his hair, long and silky between her fingers as she brushes it back so she can get a clearer look at his face.

 

The touch is enough to break his concentration, and he peers up at her. Lily strokes his high cheek bone with her thumb and gives a small smile, unexpectedly soft, and Severus surges up to kiss it from her lips.

 

This time, Sev lets his fingers trail up her skirt, climbing high on her thighs to trace the line of her knickers, following the seams in toward her groin. Lily lifts her legs, bracing her heels against Sev's arse, knees butterflying outward. Her skirt hikes up around her hips and Severus runs his thumb down the crease of her pussy, stroking her through the damp lace.

 

“Ohh!” Lily exclaims, falling back onto the desk, hips hitching.

 

Sev hums, smirking as he drags his chin back down her body, falling to his knees.

 

“Sev...!” she moans as the Slytherin presses his nose to her panties, shamelessly inhaling the thick scent of her, tongue licking the trace of wetness as his fingers brush the red curls visible through the sheer fabric. He hooks his fingers into the waistband of her knickers, and Lily gets the hint, lifting her hips so he can slide them off her legs, leaving her in nothing but the knee-high socks and skirt puddled around her waist.

 

Severus exhales hotly against her mound, nose buried in her red hair as his tongue laves her eagerly, his fingers coming up to prod at her slit, delving tentatively inside.

 

“Yeah, like that,” she encourages him, feet planted on the desk. She fists her hand in his hair, pulling harshly, but he doesn't complain. His tongue laps at her clit and she thanks God for those Slytherin workshops, because they certainly knew what they were teaching. Long fingers press into her, two at once, crooking to rub at the spongy flesh of her G-spot, the feeling of him better than anything she'd ever done to herself.

 

Lily rocks her hips forward, riding his fingers. He licks her engorged clit into his mouth, sucking hard and Lily screams, the sound echoing loudly off the classroom walls, and she only just has the presence of mind to feel around for her wand and cast a silencing charm.

 

“Severus, please!” she begs, keening. “C'mon, please – please fuck me, Sev! I need it; need you so bad, please!”

 

Severus moans helplessly, the sound vibrating through her pussy and she trembles a little at the sensation. He backs off, obediently, popping the fingers which had been buried inside her into his mouth, licking her sticky juices from them. Lily groans shakily at the sight, watching as he wipes the shining wetness off his chin with the back of his hand (though his cheeks were still streaked with it) as he searches frantically through his robes. Finally he emerges, victoriously holding aloft the condom packet the sixth years had graciously provided for them.

 

Standing, he viciously attacks the buttons on his trousers, tented over his arousal.

 

“Nng...” she groans as he shoves them down his knees along with his briefs, cock bobbing up against his stomach, leaving a smear of precome. It's long and thin like he is, thick dark hair at the base and she licks her lips hungrily when he fists it a few times, spreading the wet precome along his length before tearing into the condom packet and rolling it onto his shaft.

 

Lily keeps her legs spread wide as Sev comes up between them, positioning the tip of his cock at her entrance. He's shaking with nerves, hesitation marring his features as he looks up at her for reassurance. He looks young and unsure and for the first time Lily is reminded that this is his first time, too. She smiles at him anxiously, nodding her head in encouragement as she takes his hand in hers, squeezing tightly.

 

He gives a small smile in return, squeezing back, and then...

 

And then.

 

“Oooohhh!” Lily cries out, head crashing hard into the table, eyes impossibly wide, back arching at the overwhelming _fullness_ , nothing like fingers inside her. There's a slight burn of a stretch, but it's perfect and Sev is slow going, but doesn't stop, seating himself inside her then dragging back out. She blinks rapidly as he thrusts in again, thighs quivering, and she whimpers, face scrunched up in agony because it's so fucking perfect and she wants it so much - !

 

Severus feels the same, she can tell, or worse. His eyes are clenched tight and sweat drips down his red face as he tries to breathe shakily through his nose. His hand is squeezing hers hard enough to hurt, but she doesn't want to let go, needs that grounding connection as much as he does.

 

“Faster,” she pleads, voice small and high.

 

Severus shakes his head rapidly. “Can't,” he gasps out. “I can't – fuck, Lil! If I go any faster this'll all be over because I'm going to come, you have no idea...!” He keens lowly, staving off his impending orgasm, and Lily feels a little proud for getting him so worked up so quickly, but doesn't want this to be a two thrust bust, nor does she want Sev to embarrass himself like that, so she tugs him down over her, letting him bury his face between her breasts, stroking his spine as he calms down.

 

Slowly, his breathing evens out and the trembling stops, muscles unclenching. He pulls their joined hands up by Lily's head and she turns to press a kiss to his knuckles as he noses up to her neck, bracing himself on his forearm as he starts to move again. Lily wraps her legs around his waist, pulling him in deeper, and now that the threat of premature ejaculation has mostly passed, his thrusts are faster, harder, and Lily feels her own orgasm building back up again.

 

She keeps her arm wrapped around his back, nails scratching at his shoulder blades, but Sev doesn't seem to mind. He turns his head to mouth at her jaw as he speeds up, their skin slapping together obscenely in the otherwise quiet classrooms, the only other sounds their heavy breathing and the grunts being punched out of their throats with every thrust, Severus's voice dangerously low, and Lily's a higher pitch than she's ever achieved before (it's weird, and she's a little self conscious about it, but Sev hasn't stopped kissing her yet, so she's not going to worry about it right now).

 

“Sev,” she sighs, kissing the sweat from his hairline, inhaling the crisp scent of his shampoo along with the heady musk of _him_ that she knows so well.

 

His head comes up and he catches her eye, his own over-bright and wild and she can't imagine how _she_ looks to him, but he kisses her again, their mouths moving together sweetly, desperately.

 

“Are you close?” he asks against her mouth and she nods. “Thank God,” he sighs in relief, licking back into her mouth, thrusting fast and hard, erratic and she's probably going to have a bruised pelvis or something but she certainly isn't complaining because oh, my _God_ -

 

She squeezes her eyes shut and arches her whole body up into him, grinding her teeth to stop from screaming but the sound comes out anyway, only barely muffled and still piercingly loud, and she thinks Severus winces a little, but then she clenches around him and he's crying out, too, louder than she's ever heard _him,_ and for one irrational second she hates that fucking condom because she wants to really _feel_ him.

 

But he keeps rocking into her, minutely as he empties himself into the rubber, Lily's orgasm still sending aftershocks through her body, and she's satisfied, she's so, so happy and she squeezes him, legs tight around his waist because she wants him closer. Here. Hers.

 

He blinks hard as the rocking slows to a stop. She can feel him softening inside her and she whimpers as he withdraws, standing up. He pulls the condom off, vanishing it to wherever vanished things go, and Lily sits up, wincing a little, but unwilling to have him so far away so soon.

 

“Come back,” she mumbles sleepily, hormones pushing tears from her eyes as she presses her forehead to his chest, tucking him back into his pants and buttoning his trousers, fingers lingering on the waistband.

 

“Hey,” Sev says softly, worried. “Are you all right?” he asks, fingers softly stroking the back of her neck.

 

Lily nods, keeping her face against his sternum so he can't see the tears streaking quietly down her cheeks. She's crying and she's not sure why, needy in a way she's not used to feeling, but she's good. Hell, she's great. Perfect. She wishes, not for the first time, that she had been sorted into Slytherin (because the image of Severus as a Gryffindor is ridiculous) because the only thing that would make everything even better is if they could go to sleep together, because Lily really, _really_ doesn't want to go.

 

“You sure?” he asks, thumbs wiping the tears away.

 

“I'm good,” she assures him, smiling waterily up at him. “It was perfect,” she asserts, “I'm just a little overwhelmed is all.” She sits up, sniffling as she wipes her eyes with her palm.

 

“Okay...” Sev allows, though he still looks concerned. She raises her arm to cup the back of his neck, tilting her head up for a kiss which he gives her without hesitation. She lets him kiss her better, feeling the anxiety melt out of him in turn.

 

“Was it everything you wanted it to be?” he asks quietly, forehead pressed to hers, and she grins.

 

“Even better.”

 

*

 

When she finally climbs back up to the Tower and collapses into her bed, fingers drowsily playing with the bracelet still clasped around her wrist, she thinks that this is the best birthday she's ever had.

 

**Author's Note:**

> This came out way more romantic than I knew I was capable of, to be honest. 
> 
> Obviously this is before their fall-out.
> 
> If anyone's curious, [this](http://d200fahol9mbkt.cloudfront.net/item/5721889/Vintage_Style_Butterfly_Bracelet.JPG) is the bracelet Severus gives her, [this](https://img0.etsystatic.com/027/0/5986656/il_570xN.616917724_ezsw.jpg) is the plush that James gives her, [Slughorn's desk](https://a.1stdibscdn.com/archivesE/upload/f_9859/f_3566642/modernariat_WEB_High_2093_z.jpg), and [Lily's lingerie](http://e.hprints.net/md/40/40521-valisere-lingerie-1975-hprints-com.jpg).


End file.
